July 9, 2010 AT 5:24 pm

HOW TO – Make a solar MintyBoost, a solar power charger for your gadgets!

Previously there was a very popular Instructable on making your own “Solar MintyBoost” – before you needed to get parts from various places, now you can get them all in one spot – at the Adafruit shop!

Choose from either a 1W or 2W solar panel. Either will work, if you are using the smaller panel, we suggest removing R4 and replacing it with a 6.8K (or so) resistor which will keep the lipoly charger from trying to draw too much current from the panel.

Next up, you’ll need a mini-B USB cable to sacrifice. Use the one in the shop or find one in your room.

Note: While it may most devices, this will mostly likely not work consistently with the iPhone 3Gs and/or the iPhone 4. We will have a new MintyBoost and MintyBoost “rechargeable” soon, if you need to support those two devices specifically hold off until you see these new versions of our kits on our site.

Ok, so I’m still learning, and all these resistor properties are making my head spin here.
I plan on making this entire kit from the solar panel to the minty boost but I’m going to use the smaller solar panel so I can keep it all compact.
What I need to know is what do you mean by "removing R4 and replacing it with a 6.8K (or so) resistor"? Do you mean the R4 resistor from the mint boost kit? Or do you have to build the LiPol charger and replace an R4 position resistor?
Not to show my infancy in electronics. A 6.8K resistor would be one with a banding of Blue, Gray, Red, and the last one will either be yellow(5%),silver(10%),or gold (20%)tolerance, or a 6,800 ohm resistor (+/- tolerance). Is that correct?
Oh, and what is the "or so" about?

the lipoly charger is prebuilt, but if you look carefully you will see there is a way to solder in a thruhole resistor in spot R4 – this can change the charging rate. by adjusting the charge rate you can get the best efficiency from your panel.

“or so” means that if the shop doesnt have exactly 6.8K you can vary it by up to 10 or 20%

Is there away to charge the battery pack from house power? I do a good deal of hiking and would like to be able to leave with the battery fully charged and then charge it from the solar panel when needed. THanks for you help!

adafruit…
Will this work with an iPhone4 if you have the v4 MintyBoost to recharge? There is a disclaimer at the bottom of the description that states:

“Note: While it may most devices, this will mostly likely not work consistently with the iPhone 3Gs and/or the iPhone 4. We will have a new MintyBoost and MintyBoost “rechargeable” soon, if you need to support those two devices specifically hold off until you see these new versions of our kits on our site.”

Is this true or is this just old and the v3 addresses this issue?
Thanks
John